SPC/E model of water: Difference between revisions

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m (slight reparametrization)
m (Updated figure)
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The molecule is modelled as
The molecule is modelled as
a rigid isosceles triangle, having charges situated on each of the three atoms. Apart from Coulombic interactions, the molecules interact via long-range [[Lennard-Jones model | Lennard-Jones]] sites, situated  on the  oxygen atoms. The parameters are as follows:
a rigid isosceles triangle, having charges situated on each of the three atoms. Apart from Coulombic interactions, the molecules interact via long-range [[Lennard-Jones model | Lennard-Jones]] sites, situated  on the  oxygen atoms. The parameters are as follows:
[[Image:Water_empirical1.png|center|300px]]
[[Image:Thee_site_water_model.png‎|center|400px]]
{| border="1"
{| border="1"
|-  
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|-
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| <math>q_{\mathrm{H}}</math> ||  <math>q_{\mathrm{O}}/2</math> (charge neutrality)
| <math>q_{\mathrm{H}}</math> ||  <math>q_{\mathrm{O}}/2</math> (charge neutrality)
|-
| <math>r_\mathrm{OM}</math> ||  <math>0</math> (charge sits on oxygen)
|}
|}
The SPC/E model has a [[dipole moment]] of 2.351 D. (Ref. 1 Table I),
The SPC/E model has a [[dipole moment]] of 2.351 D. (Ref. 1 Table I),

Revision as of 17:22, 8 June 2009

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The extended simple point charge model, SPC/E is a slight reparameterisation of the SPC model of water, with a modified value for . The molecule is modelled as a rigid isosceles triangle, having charges situated on each of the three atoms. Apart from Coulombic interactions, the molecules interact via long-range Lennard-Jones sites, situated on the oxygen atoms. The parameters are as follows:

parameter value
kJ mol-1
(charge neutrality)

The SPC/E model has a dipole moment of 2.351 D. (Ref. 1 Table I),

References

  1. H. J. C. Berendsen, J. R. Grigera, and T. P. Straatsma "The missing term in effective pair potentials", Journal of Physical Chemistry 91 pp. 6269 - 6271 (1987)
  2. Swaroop Chatterjee, Pablo G. Debenedetti, Frank H. Stillinger, and Ruth M. Lynden-Bell "A computational investigation of thermodynamics, structure, dynamics and solvation behavior in modified water models", Journal of Chemical Physics 128 124511 (2008)